Key lime pie is a fantastic summertime dessert. It’s cool, creamy filling and bright sweet-tart lime flavor is refreshing even on the hottest day. This Key Lime Chiffon Pie is an even better choice. The pie has all the flavor of a traditional key lime pie, but in a form that is even lighter and requires absolutely no baking. Chiffon pies have a mousse-like filling that is lightened with egg whites and whipped cream. To separate them from regular mousses, chiffon fillings are also held together with a small amount of gelatin that firms them up just enough to make them slice-able.

The filling has a smooth, creamy texture and a nice balance of sweet and tart to it. You get a big lime flavor in every bite, which will make this a hit with citrus-lovers. Just as I like a graham cracker crust in a classic key lime pie, it also works very well with this filling by giving the pie another layer of flavor and texture. It is lighter than a traditional pastry crust, so it doesn’t weight down the fluffy filling and you won’t feel heavy even after eating a generous slice of this dessert. Because this is a no-bake pie, the filling comes together very quickly and easily. You will have to wait a little while for the filling to set up in the refrigerator before serving, but you can always save yourself a few spoonfuls to snack on while you wait for the whole pie to be ready.

The recipe makes enough filling for a deep dish 9-inch pie crust. I used a homemade graham cracker crust for this pie, and was able to use up just about all of the filling. If you are using a storebought crust, keep in mind that those tend to be much shallower and you will probably have filling left over. You can use it up by picking up some mini graham cracker crusts and filling those up, as well, or by simply pouring the filling into dessert cups and serving them separately, with a dollop of whipped cream. The pie is the best within a day or two of making it and should be stored in the refrigerator.

In a small microwave-safe bowl, combine lime juice and gelatin. Allow mixture to stand for 5 minutes to soften the gelatin. Microwave for 30-40 seconds, stirring to ensure that the gelatin is completely dissolved. Set aside to cool slightly, about 5 minutes.
In the bowl of a stand mixer or other large bowl (preferably metal), beat together egg yolks and sugar until mixture has tripled in volume and sugar is completely dissolved. Stir in lime zest and cooled gelatin mixture until well combined.
Prepare an ice bath and place the bowl containing the gelatin mixture over it to cool it quickly. Stir it occasionally, until it is the consistency of thick pancake batter, about 10-15 minutes. When it has thickened, whip with a small whisk to remove any lumps.
In a small bowl, beat heavy cream to soft peaks. Add to cooled gelatin mixture and fold in until well-combined.
In a medium bowl, beat egg whites to stiff peaks. Fold in to cooled gelatin mixture.
Pour chiffon into prepared pie crust. Refrigerate until firm, about 4 hours.